Capsule cleaning device



Dec. 29, 1959 J. H. LAKE CAPSULE CLEANING DEVICE Filed May 6. 1957 m m m. WH S E M A J ATTORNEYS FIG. 1

UnitcdStates Patent CAPSULE CLEANING DEVICE James H. Lake, Indianapolis, Ind., assignor to Eli Lilly and Company, Indianapolis, Ind., a corporation of Indiana Application May 6, 1957, Serial No. 657,317 4 Claims. (Cl. 15 -308) This invention relates to a capsule cleaning device. The device may be used as an accessory attachment for a capsule filling machine or it may be operated as a separate entity apart from such machine.

In filling, two-part, cap and body telescoping type capsules there is a tendency for the outside of the capsules, during the filling operations, to become covered with a powdery coating. This coating is not only unsightly and undesirable in appearance but is further objectionable in that it defeats a fundamental purpose of encapsulation, namely, the prevention of the medicament from being tasted during oral administration. It, therefore, has been the custom in the drug industry to wipe loose powder from and to polish all such powder-filled capsules before packaging them for distribution. Heretofore, the cleaning and polishing operations commonly have been performed manually. Usually this is done by depositing a quantity of the capsules at random between layers or folds of a piece of cheesecloth or the like and gently rolling the capsules between such folds with a reciprocating or circular manipulation to remove these powder particles.

This method of cleaning is quite costly and time consuming, especially, when dealing with a mass production volume of capsules. Such hand methods, in addition to requiring the employment of numerous operators, are not entirely satisfactory because frequently portions of the surfaces of a substantial number of the capsules escape any contact with the wiping cloth with resultant cleansing failure. Another disadvantage is that the wiping cloths fairly rapidly become saturated with the particular powder medicament encapsulated and this makes necessary frequent laundering and changing of the cloths. This also adds to the costs of such methods of cleaning capsules. Machines have been developed which employ an impact method of cleansing, i.e., the capsules are permitted to fall for quite some distance on a mesh screen in a chamber wherein there is maintained an air stream and reliance is placed upon the impact of the capsule to dislodge the powder and have it pas off in the air stream. Such machines have not been satisfactory because there is insuflicient positive removal of the adhering powder incident to the impact, the net result being that hand polishing operations are still required to insure complete removal of the dust.

It is an object of the present invention to provide a device which is simple in design and construction and which effects a continuous and relatively extensive automatic wiping operation for the removal of these undesirable powder films from capsules in a free-flowing, continuous, progressive and mass. production manner.

Other objects, features, innovations, elements, and combinations of the invention will be discernible from the following description which is to be taken in conjunction with the accompanying drawings.

1 In the drawings:

Fig. l is a side elevation of a capsule filling machine with my improved cleaning device shown mounted thereon,

Fig. 2 is a longitudinal elevation of the device with certain parts being broken away for clearness, and

Fig. 3 is a transverse sectional elevation taken along the line 3-3 of Fig. 2.

For exemplification purposes, the invention is illustrated herein in conjunction with a capsule filling machine of the type disclosed in US. Patent No. 1,819,936, granted August 18, 1931, to Warren Wilkie et al. It is to be understood, however, that the invention is capable of use either in association of other types of capsule filling machines or as 'a separate entity into which capsules filled in any manner, may be introduced for cleansing purposes.

Referring to Fig. 1, the capsule filling machine 10 of the type disclosed in the aforementioned patent is shown in broken lines with the capsule cleaning device of the present invention being shown in solid lines. The device comprises a horizontally disposed cylindrical housing or chamber 11 adapted to be mounted beneath a discharge funnel 12 out of which fall the the filled capsules. Herein the means for mounting housing 11 is shown as a bracket 13 affixed at one end to the exterior of housing 11 and at its opposite end to a leg 14 of filling machine 10.

The opposite ends of housing 11 (Fig. 2) are flanged as at 15 and cap plates 16 and 17 are secured as by screws 18 to flanges 15 to completely close the ends of the housing.

A spiral brush 19, coextensive in lentgh with the length of cylinder 11, is positioned therein. Brush 19 is known in the brush art as a twisted wire spiral brush. The opposed ends of the twisted wire shaft 20 of said brush are soldered, set-screwed or otherwise suitably secured within stub shafts 21 and 22. Shafts 21 and 22 are journalled for rotation in suitable bearings 23 press-fitting centrally into cap plates 16 and 17, respectively. Stub shaft 23 has afiixed to its outer end a bevelled gear 24 meshing with a bevelled driving gear 25 which, in turn, is atfixed on a horizontally disposed shaft 26 suitably journalled at its opposite ends within agear housing 27. A pulley 28 is affixed to one end of shaft 26 and is con,- nected by a belt 29 (Fig. l) to a pulley 30 fixed on a main drive shaft 31 that is associated with capsule filling machine 10. By the train of connections just described, brush 19 is continuously driven in rotation within housing 11.

The bottom of the cylindrical housing or chamber 11 may be formed by an inset wire-mesh screen 32 extending from a point adjacent cap plate 16 to a point indicated at 33 (Fig. 2), spaced from cap plate 17, the degree of inset with respect to the interior of housing 11 being slight. Referring to Fig. 3 it will be seen that this inset perforate or secreened bottom portion of chamber or housing 11 extends transversely for a distance of approximately 60 degrees of the circumference of said housing and forms an inset arcuate continuation of its cylindrical cross section. It will be understood that in lieu of a wire mesh screen, if desired, this inset portion of the bottom may be formed integrally as by upsetting and impressing inwardly the bottom portion of cylindrical housing 11 slightly and perforating such inwardly upset portion with a series of closely spaced holes or orifices. The bristles of brush 19 extend radially from the twisted wire shaft 20 preferably for a distance which places their tips flush with the interior surface of cylindrical housing 11. However, the extent of inset of the perforate or screened portion 32 with respect to the interior of the housing is sufficient to cause the tips of said bristle to extend slightly through the orifices provided therein as clearly shown in Figs. 2 and 3.

A funnel shaped duct 34 is air-tightly secured around its upper edge to the exterior surface of cylindrical housing 11 to completely and dependently surround the bottom perforate or screened portion 32 of the housing or chamber 11. At its lower end 35 duct 34 is connected by tubing 36 to an exhaust fan 37 (Fig. 1).

Housing 11 is provided with an opening 38 in its top side, above brush 19 and adjacent cap plate 16. Preferably, an upstanding tube 39 is secured around said opening and communicates with the funnel outlet 12 of the filling machine to provide an inlet channel for directing the filled capsules from discharge funnel 12 of filling machine into housing 11. A similar opening 40 is provided on the bottom side of housing 11 beneath brush 19 and adjacent cap plate 17 to provide an outlet for egress of capsules from within housing 11. A tube 41 may be, and preferably is, provided to convey the cleaned capsules into a suitable receptacle such as 42 (Fig. 1).

Exhaust fan 37 is of a capacity such as will produce an exhaust air stream of suflicient velocity through capsule inlet tube 39, housing 11, the bristles of brush 19, duct 34, and tubing 36 to entrain any and all dust particles which become freed to its influence.

The particular helical pitch of the bristles of spiral brush 19 has been found to be not too critical but the pitch should be in the range of one-half to three-fourths of an inch to produce most effective cleaning results. In practice it has been found desirable to have brush 19 rotated within cylindrical housing 11 at approximately 300 r.p.m.

Housing 11 may be, and preferably is, mounted at an angle as shown so as to incline the capsule discharge end of the housing upwardly. Such angular placement of the housing tends to delay the advance of the capsules along the helical path and thereby extends the period of time during which the capsules will be rubbed and wiped by the bristles of brush 19.

In operation, the filled capsules descend by gravity through inlet tube 39 and through opening 38 into the helical path formed by the spirally arranged bristles of brush 19. Rotation of brush 19 causes the capsules to be advanced along said helical path and, during their traverse therealong, the capsules are turned end-over-end in a toppling fashion. As they are advanced along the path in this manner they are thrust against the sides of the bristles and a wiping action is effected primarily along the sides of the bristles during this forced traverse of the capsules along the path. The bristles are of sufficient resiliency, however, so that upon a mass of capsules entering within housing 11 one or more capsules may be crowded or squeezed between the bristles transversely thereof or, in certain instances, may pass under the tips of the bristles. transparent housing 11, constructed for such purpose have demonstrated that the capsules, in the main, are simply progressively advanced along the spiral path formed by the bristles and that substantially all of the dust-removing action is effected by their being brushed or wiped upon the sides of the bristles incident to their, impingement thereagainst. When the capsules reach the end of the helical path they fall through opening 40 into tube 41 and are directed thereby into receiving hopper 42.

Since the openings in the inset perforate or screened bottom portion 32 engage the tips of the bristles of brush 19, the bristles will, as clearly shown in Fig. 3, deflect slightly as, they sweep past the openings in such bottom portion. This results in a repetitive'flexing and unflexing action upon the bristles andimparts vibration of sufficient magnitudeto shake the dust particles collectedthereupon loose from the bristles. The loosened dustparticles immediately become entrained in theexhaustair stream and are carried away thereby. v i b From the foregoing it will readily be understood. that,

However, observations made through a v if desired, the device may be operated separate and apart from a filling machine with an independent suitable driving means provided for imparting continuous rotation to brush 19. In such event, of course, the filled capsules to be cleaned will be dumped into a suitable supply hopp er positioned over opening 38 in housing 11 to feed the capsules into the housing.

It should be understood that the present disclosure is for the purpose of illustration only and this invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

1. A capsule cleaning device comprising a substantially horizontally disposed, cylindrical chamber having closed ends; a spiral brush having multiple convolutions of bristles and a uniform outer diameter substantially equal to the inner diameter of the chamber and coextending longitudinally of said chamber and journalled at its opposite ends in the opposed ends of said chamber; the spaces between the convolutions of the bristles of said brush forming a helical path for advancing capsules continuously and progressively from one end of said brush to the other and being of such width as to substantially just accommodate the width of the capsules; means as sociated with said brush for driving it in rotation in said chamber; a capsule-receiving tube communicating with one end of said chamber from. the top thereof; a capsule discharge tube communicating with the opposite end of said chamber from the bottom thereof; said bottom of said chamber having a perforate portion extending longitudinally of the chamber from a point adjacent said discharge tube to a point beneath said capsule-receiving tube; an exhaust fan; and duct means surrounding said perforate portion and connected with said exhaust fan for producing a dust-entraining air stream through said capsule-receiving tube, said chamber, said brush bristles and the orifices of the perforate portion of said bottom.

2. A capsule cleaning device according to claim 1 wherein said brush is so positioned within said chamber that the tips of said bristles constituting said brush lie substantially flush with the interior of said chamber but project slightly into the orifices of the perforate portion of said bottom to produce a flexing and releasing vibrating action to said bristles.

3. A capsule cleaning device comprising an angularly disposed cylindrical housing having its opposite ends closed; the bottom of said housing being formed by an inset screen portion extending from one of said closed ends to a point spaced from the opposite of said closed ends; a spiral brush having a uniform outer diameter substantially equal. to the inner diameter of said housing and extending longitudinally within said housing and having its opposite ends journalled for rotation in the opposite ends of said housing; the spaces between the turns of the bristles forming said. brush corresponding substantially to the width of the capsules to be cleaned; means associated with one end of said brush for driving it in rotation within said housing; an upstanding capsule inlet tube communicating with said housing adjacent that end thereof above said screen portion for ingress of capsules into said housing; a depending capsule outlet tube communicating with said housing adjacent that end thereof which is spaced from said screen portion for egress of said capsules therefrom; an air exhaust fan; duct means surrounding said screen member outwardly of said housing and communicating with said exhaust fan and effective to establish an air stream through said capsule inlet tube, the bristles of said brush, and said housing; whereby capsules introduced into said inlet tube enter said spaces between said turns of said bristles and are advanced along the helical path formed by said bristles with the dust on said capsules being wiped therefrom by contact primarily with the side surfaces of said bristles, said dust being constantly removed from said housing and said bristles by said air stream as augmented by the repetitive flexure and release of said 5 bristles as their tips vibrate past said screen portion of said housing.

4. A capsule cleaning device comprising a closed-ended, substantially horizontally disposed, cylindrical housing having an opening at the top adjacent one end thereof to receive capsules to be cleaned and an opening at its bottom adjacent the opposite end thereof for discharge of cleaned capsules; an inset longitudinally extending portion of said bottom being perforate; an exhaust fan; duct means surrounding said bottom perforate portion and communicating with said exhaust fan to produce an air stream through said capsule-receiving opening and said housing; a spiral brush extending longitudinally through said housing with its opposed ends journalled for rotation in the ends of said housing; the spaces between the convolutions of the bristles constituting said brush corresponding in width substantially to the width of said capsules and the ends of said bristles terminating substantially fiush with the interior of said cylindrical housing but entering within the perforations of said inset, perforate, bottom portion thereof; and means associated with said brush for driving it in rotation; whereby capsules entering said capsule-receiving opening are continuously and progressively ad vanced along the helical path formed between the convolutions of said brush and thrust against and wiped primarily upon the sides of said bristles during their endover-end, toppling traverse along said path; the wiped dust being constantly vibrated loose from said bristles as their ends successively sweep over said perforate portion; all of said dust becoming entrained in and being carried off by said exhaust air stream.

References Cited in the file of this patent UNITED STATES PATENTS 527,590 Carlson Oct. 16, 1894 1,007,666 Baldwin Nov. 7, 1911 1,676,306 White July 10, 1928 2,042,896 Hofler et a1. June 2, 1936 2,425,984 Blackrnan Aug. 19, 1947 2,732,987 Moore Jan. 31, 1956 

